i965: Drop BRW_NEW_VERTEX_PROGRAM from Gen7+ 3DSTATE_VS atoms.

i965: Drop BRW_NEW_VERTEX_PROGRAM from Gen7+ 3DSTATE_VS atoms.

We don't access brw->vertex_program or ctx->_Shader since the previous
commit, so we don't need this dirty bit.

I think it's still necessary on Gen6 because it still conflates
constant uploading with unit state uploading.  We can fix that later.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>